A hybrid numerical-experimental strategy for predicting mechanical response of components manufactured via FFF

Abstract

In this paper a new methodology developed for predicting the mechanical performance of the structures additively manufactured by Fused Filament Fabrication is presented.

The novelty of the approach consists in accounting for the anisotropy in the material properties induced by the printing patterns. To do so we partition the manufactured structure according to the printing patterns used in a single component. For determining the material properties of each partition, a hybrid experimental/computational characterization is proposed.

The external partitions with aligned (contour) and crossed (cover) filaments are characterized through uniaxial tensile tests on General Purpose Acrylonitrile Butadiene Styrene dog-bone samples with corresponding patterns. Characterization of the inner structure (infill/lattice) is done through computational homogenization technique using Representative Volume Element.

The presented methodology is validated against experimental results of square cross-section demonstrators. It is shown that the material properties depend on the geometrical relationship of the different printing patterns, exclusively. Therefore, the exhaustive experimental procedure can be avoided characterizing the printed material by a pre-defined anisotropic constitutive relationship proportional to the properties of the raw material. Moreover, the acquired geometrical relationship is validated for components made of Polylactic Acid.

The given methodology may be used as design-for-manufacture tool for creating functional components.